Time shifting is usually done with a video cassette recorder (VCR) and its timer function, when the VCR tunes into the appropriate station and records the show onto VHS tape. In recent years, the advent of the digital personal video recorder has made time shifting easier, by recording shows onto a hard disk and using a program guide. A digital PVR also brings in new freedom for time shifting, as it is possible to start watching the recorded show from the beginning even if the recording is not yet complete.
The ability and legality of time shifting programming was determined by a landmark United States court case of Sony Corporation v Universal Studio Productions, when Sony argued successfully that the advent of its Betamax (1976) video recorder did not violate the copyright of the owners of shows which it recorded.
In 1979, Universal sued Sony, claiming its timed recording capability amounted to copyright infringement. However, a district court found that noncommercial home use recording was considered fair use and ruled in favor of Sony. In appeals, the U.S. Court of Appeals reversed this decision in 1981 giving the edge to Universal, but the U.S. Supreme Court reversed it yet again in 1984, and found in favor of Sony 5-4. The majority decision claimed time shifting represented no substantial harm to the copyright holder, and would not contribute to a diminished marketplace for its product. Today, this is widely referred to as the Betamax Case or Betamax Decision.